Hydraulic jack.



J. W. NELSON.

HYDRAULIC JACK.

APPLICATION FILED NOV.26. 1909.

19149,?9. I Patented Aug. 10, 1915.

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HYDRAULIC IACK.

APPLICATION FILED NOV.25| |909.

WIT/VESSES INI/ENTO? l I f n Y www By Wfm Patented 10, 1915.

FFICE.

JAMES W. NELSON, 0F NEW YORK, N. Y.

HYDRAULIC JACK.

Specication of Letters Patent.

Patented Aug. 10, 1915.

Application'led November 26, 1909.l Serial No. 530,031..

The principal object of the present invention is the provision of means for facilitating the operation of lowering the jack; z'. e., releasing the liquid which is conlined under pressure in the ram chamber and permitting the same to flow back into the reservoir or other source of supply, whereby the expanded parts of the jack may be contracted for the next succeeding operation.v

In my earlier patent aforesaid, I have shown and described an independent device for unseating the pump valves and thus providing an lopen passage from reservoir to ram chamber. Under some conditions, however, it is desirable that a jack be provided, in addition to this independent lowering mechanism, with means whereby the jack may be lowered by movement of the pump-lever through a. distance somewhat in excess of the usual maximum effective pumping stroke. Furthermore, it is well known that the ram in this type of jack, as a'rule, is made up of three separate parts;

viz., a cylinder closed at its lower end, a

pump block in said cylinder, and a head t0 which said cylinder is secured, the last providing a reservoir for the Iiduid'employedl and containing the Ypump actuating mechanism. As these parts are usually secured together by screw-threaded connections, it will be apparent that their relative positions, when assembled, are not readily predeterminable. Therefore, with the valves in fixed locations lafter the parts of the jack have been assembled, and these locations being unpredeterminable with respect to the position of the head which also contains the vvalve actuating means, it will be apparent that such valve actuating means should be of such a character as to be operable irrespective of the positional relations of the other cited. p

My invention will be more readily understood by reference to the accompanying drawings, forming apart of this specification, in which-- I Figure l is a central vertical section of a hydraulic jack embodying' my invention; Fig. 2 is a section taken substantially on the line 2 2 of F ig. 1, and Fig., 3 is a section on the. line 3-3 of Fig. 1.v

Referring now to the drawings in detail, numeral 6 refers to the ram cylinder which is provided with the heavy and preferably integral base 7. The ram comprises the c vlindrical member 8 `which is bored to provide an upper pump chamber 9 `near the bottom thereof and a lowerpump chamber 10 of smaller diameter below the chamber 9. These pump chambers are some` times provided by the insertion of a suitable pump-block in the bottom of the cylinder which provides the ram, although in this case I have shown an integral ram member.l

The upper end of the member 8 is screwthreaded for the reception of the head 1l which is provided with a correspondingly screw-threaded seat therefor. This head 11 provides an interior chamber 12 for the liquid employed, and in this head is located the pump actuating mechanism. Thisv mechanism comprises a rock shaft 13 projecting to the exterior of said head, Where it is provided with the usual pump-lever. Upon this shaft is secured the arm 14 which terparts of the jack hereinbefore re- "minates in a knuckle 15 projecting into the valve 23 which has the stem 24 projecting upwardly in said bore. At 25, said bore is again increased in diameter to provide a seat for the valve 26 which has a stem 27 projecting upwardly and extending nearly but under normal conditions not quite to the valve 23. In order to again reduce the now increased diameter of said bore at the lower end thereof, I provide a removable cylindrical ,plug 28 which provides" a seat for the valve 29 which has a stem 30 projecting upwardly and extending nearly but under normal conditions not quite to the valve 26. I prefer that the lower valve 29 should be spring-seated, as shown.

A lateral bore 30 connects the lchamber 31 within the ram member 8 with the bore 21 above the valve 23. Another lateral bore 32 connects the chamber 9 below the vlarger pistons with said bore 21 between the valves 23 and 26. Similarly, a lateral bore 33 connects'the chamber 10 below the small piston with the bore 21 above thelowest valve 29.'

It will be apparent that with each of these valves free yto perform its usual function, upon the up-stroke of the piston-rod 17 partial vacuums will be created in the chambers 9 and 10 below the istons 18 and 20, respectively, the inequalities of pressure resultin in the unseating of the valves 23 and 26 an a flow of liquid from the chamber 31,

andthe chamber 12in the head 1,1, past' said valves and into the chambers 9 and 10.

-Upon the down-stroke of the piston rod 17,

the valve 23 will be seated by the excess of pressure underneath the same, and the liquid `will be forced under pressure past the valve 29 and into the Aram o r pressure chamber 34.

Slidably mounted in the top of the chamber 31 in the ram'` chamber 8, is the cylinder 35, the upper end of which is provided with .a flange or rim 36 which projects` to both sidesof the body portion of said cylv liquid from a central aperture 37 for vthe and 'to permit of the flow of the chamber 12 to the chamber 31. In the vbore 21 is located a rod 40, the

inder, leavin piston vrod y1 'lower end of which is located in contact with or just above the uppel end of the stem-24 of the valve 23.- This rod 40 is upwardly spring pressed and normally held clear of the valve stem 24 by means of the spring 38, in compression between the shoulder 39 and the pin 41 in said rod, rod contacting with the flange of the cylinder 35 and serving to. return the latter to normal .position when it has ,been depressed. In the head 11 is mounted a short shaft 42 onthe inner end of which is fixed the cam 43, located to act against the ange or rim 36 of the cylinder 35. AAt the outer end of the shaft 22 is provided a head I 44,`carrying a lever 45 by y"means vof which the shaft 42 may be rotated to actuate the cam 43. f t

It will now be apparent that when it is desired to hold the upper valve 23 oil' its seat, as is necessary when vit is desired to sacriice speed for power under the well known principles of hydrostatics by decreasing the piston area,

the upper end of said or rim 36 the lever 45 is turned torotate cam 43, which impinges `against the flange 36 and forces downwardly theI red 40 to the point where.v the valve 23 is unseated. v Under these conditions,

the up-stroke of the piston, will upon the the liquid `which is drawn into the chamber 9 upon down stroke thereof follow the ,pathylgofi f least resistance and flow. idly back through thebore 32, past the"valve 23 and through the bore 30 to the chamber 4p31, ,lt will be y furthermore apparent.. all of thefvalves A in said bore 21 may be'y unse'ate dbyf ,defpress-l ing the rod 40 a suiiicientfdistance'that the valve 23 has impinged'a'gainstl .the'stemjf27' and unseated the valvef26,`fwhich, inturn, impinges against the vstem '30,uand unseats the valve 29, all of these valves' being inthis manner held off their Seatsand providing an open passage to the reservoir flow back to said reservoir andthe parts of the jack be again contracted for the next succeeding operation. It .is obvious, of course, that the rod 40 may be depressed in from the ramfchamber 34'.` 12, so vthat the liquid will I this manner and to this extent by continued rotation of the cam 2,3, but inasmuch 'as this operation is entirely rindependent of the pumping operation and makesit necessary l for the man who is operating the pump tov release the pump lever and carefully the lever 45 through the proper 'arc,'and inasmuch as the oldmethod ofV74 .loweringturn through manipulation of the pump lever y itself would undoubtedly require less time, I provide the head 16 with a downwardly projecting pin 46 which, upon the normally effective stroke of the piston-rod, does not impinge against the flange or rim 36 of the cylinder 35, but which is `of such length andso positioned on said head 16'thatwhen the downward stroke ofsaid piston-rod is increased beyond the normally effective stroke, the end of said pin 46 will impinge against said flange or rim 36 and depress the rod 40 in the-manner cessively unseat all of. the valves in the bore 21. l

It will be noted that they bore 21 is perma nently positioned with respect tothe other parts of p oted that the cam 43 and -itsmactuating described to sucthe ram member l8. It will also be mechanism and the pin 4 6 arepremanently positioned with respect to the other' parts of the head v11. It willfur lh'ermcynf@J ybe',noted;

that when the ram'member -andits head Aare secured to each other bymafs'crew-threaded connectionwhich has beenfoundtobe byA q vall means the preferable form of connec nently positioned valve-actuatingrod in one member, and permanently positloned means for actuating said rod in the other member,

v tion--it is impossible, or at least utterly y practicable, to cut screw-threads in such a way'asy to predetermine thel ultimateposi-f` tional relation ofthe two parts when con` nected together. Therefore,v with`a perman in such a manner as to insure these parts be- `with a ram comprising a body portion and ing brought into proper coperative relation, it is of the greatest importance that some means be interposed between said rod and its actuated means which will insure opera-tion of said rod entirelyirrespective of the positional relation of the ram member to the head which is mounted thereon. It will therefore be apparent that in providing the flanged cylinder 35, the flange of which 1n any position of rotation impinges against the upper end of the rod 40 and receives the action of the cam 43 and is in position to be engaged by the pin 46, I have provided means whereby one or more of the valves in the bore 21 may be unseated by means ofthe lever 45 or by means of the pump lever, irrespective of the positional relations of the ram member 8 to the head 11.

Having thus described a practical and convenient embodiment of my invention, I claim as new and desire to secure by Letters Patent:

1. In a hydraulic jack, the combination', with a ram comprising a body portion and head secured thereto in non-predeterminable positional relation, said body `portion lcontaining the pump valves and a rod actL ing against one of said valves to unseat said valve only or all thereof, and said head being provided with means for actuating said rod, of means interposed between said actuating means and said rod to insure coperative action irrespective of the relative positions of said body portion and said head.

2. In a hydraulic jack, the combination, with a ram comprising a body portion and a head secured thereto, said body portion containing the pump-valves'and means for their Vmanual control, and said head containing the pump actuating mechanism and being provided. with independent means for actuating said valve controlling means, of interposed means for insuring coperative action between said independent 'actuating means and said controlling means and for actuating said controlling means from the pump mechanism,` irrespective of the relative positions of said body portion and said head.

3. In a hydraulic jack, the combination.

a head secured thereto, said body portion containing the pump valves and a rod acting against one of said valves to unseat saidk valve only or all thereof, and said head containing the pump actuating mechanism and being provided with independent means for actuating said rod, of interposed means for insuring coperative action between said independent actuating means vand said rod and for actuating said rod from the pump mechanism, irrespective of the relative posi-- tions of said body portion and said-head.

4. In a hydrauhc jack, the combination,

with a ram comprising a body portion and a head secured thereto, said body portion containing the pump valves and means for their manual control and said` head containing the pump actuating mechanism which is also provided with means for actuating said valve-controlling means, of interposed meansv for insuring coperative action between said valve controlling means and both of the actuating means therefor irrespective of the relative positions of said'body and Said hcad.

5. In a hydraulic jack, the combination, with a ram comprising a body portion and a head secured thereto in non-predeterminable positional relation, said body portion containing the pump valves and means forv their manual control and said head containing the pump actuating mechanism which is also provided with means for actuating said valve-controlling means, of interposed means for insuring coperative actionv between said valve controlling means and both of the actuating means therefor irrespective of the relative positions of said body and said head.

6. In a hydraulic jack, the combination with a ram comprising a body portion and a head secured thereto, said body portion containing the pump valves and a rod acting against one of said valves to unseat said valveonly or all thereof, and said head containing the pump actuating mechanism which is also provided with means for actuating said rod, and said head being further provided with independent means for actuating said rod, of interposed means for insuring coperative action between said rod and both of vsaid actuating means irrespective of the relative positions of said body portion and said head.

7. In a hydraulicI jack, the combination, l

with a ram comprising a body portion and a head secured thereto 1n non-predetermmable positional relation, said body portiontaining the pump actuating mechanismv which is also provided with means' for actuating said rod, and said head being further provided with independent means for actuating said rod, of interposed means for insuring coperative action between said rod and both of said actuating means irrespec tive of the relative positions of said body portion and said hea 8. In a hydraulic jack, the combination, with a ram comprising a body portion and a head securedV thereto, said body portion containing the pump boreand a series of interdependently controlled pump valves, of a rod acting against one of said valves to unseat said valve only or all of said valves, a cylinder slidable in said bore and adapted upon depression to depress said rod, and means in said head for depressing said cylinder.

9. In' a hydraulic jack, the combination,

with a ram comprising a body portion and a head secured thereto, said body portion a flange projecting over the upper end of said rod, and means 1n said head acting against said rcylinder to depress the same.

In testimony of the foregoing, I have 15 hereunto set .my hand in the presence of two Witnesses.

- JAMES W. NEnso'N.

Witnesses: l

FRED H. Bownnsoox, P. FRANK SONNEK. 

